Method of and machine for skiving



July 25, 1939. H. LYON METHOD OF AND MACHINE FOR SKIVING s sheets-sheet1 Filed Oct. 29, 1936 July 25, 1939. H. LYON METHOD OF AND MACHINE FORSKIVING Filed Oct. 29, 1936 3 Sheets-Sheet 2 WW Gull my, v

July 25, 1939. H. LYON METHOD OF AND MACHINE FOR SKIVING 3 Sheets-Sheet3 Filed Oct. 29, 1936 Patented July 25, 1939 METHOD OF AND MACHINE FORSKIVING Harry Lyon, Abington, Mass, assignor, by mesne assignments, toGeorge A.

Mass.

Huif, Brockton,

Application October 29, 1936, Serial No. 108,180

16 Claims. (Cl. 12-67) This invention relates to methods of and machinesfor skiving strip material, and more particularly the ends of suchmaterial to form mating bevels such that the strips may be assembled andcemented together to form a continuous strip. This. may be done, forexample, to unite strips of leather in continuous form as may be desiredwhen making continuous welting for shoes or the like.

One of the objects of this invention is to produce a straight cut,avoiding the use of a roll to feed the work to the knife. By this meansany inaccuracies due to the conformation of the work being skived to acurved surface are avoided,

Another object is to provide automatically for a change of the angle ofbevel in the scarf in accordance with the thickness of the work. Thischange may be proportional, or less or more than proportional to thethickness variations as desired. More than proportional produces athicker end edge, the thicker the stock, which is often desirable.

A further object is to cut crosswise of the length of the strip by areciprocating motion and to so form the knife edge that a shear cut isproduced.

Still another object is to clamp the work over a substantial area duringthe skiving operation either against a supporting table or against theknife.

Further objects and advantages will appear from a more completedescription of an embodiment of the invention shown in the accompanyingdrawings in which Figure 1 is a side elevation of the machine.

Figure 2 is a perspective view showing one manner in which the matingfaces of two strips may be skived by the machine.

Figure 3 is a horizontal section on line 3-3 of Figure 1.

Figures 4 and 5 are detail sections on lines 4-4 and 5-5, respectively,of Figure 3.

' Figure 6 is a detail vertical section on line 6--6 of Figure 1.

Figure 7 is a detail section on line 1-4 of Figure 6.

Figures 8 and 9 are views similar to Figure 7, but showing the relationsof the parts in successive stages of a skiving operation.

'Figure 10 is a detail section on line Ill-40 of Figure 9'.

Figure 11 is a fragmentary perspective showing the relationship ofcertain of the parts to the work prior to the skiving operation.

Referring to the accompanying drawings, at 'l is indicated a machine bedon which'is mounted a slide 2. Asshown this slide is carried betweenupstanding side edges 3 of the bed, and isheld in position by strips 4secured to the upper faces of the extensions 3, and projecting over thetop face of the slide. This slide is provided with spaced upstandingbracket portions 5 and 5 and between them is provided with a centralupstanding rib provided with horizontal shoulders 8 near its lower edge.Riding on these shoulders 8 is a bifurcated wedge block 9, the 10 forksll] of which engage on opposite sides of the rib i above the shoulders8. This wedge block, as shown in Figure 1, has a threaded extension IIat one end through which is passed the .threaded portion I2 of a shaftl3. This shaft ll I3 is journaled through the bracket 5 and is held fromaxial motion relative. thereto as by the collars l4 secured to the shaftat opposite faces of the bracket 5. By turning the knurled head l5 atthe outer end of' the shaft 13, the wedge block may be moved axiallyalong the shoulders 8.

The upper inclined face of this wedge block engages beneathcorrespondingly beveled flanges 16 on a work support I! whichis ofinverted U cross section. This Work support is provided in one of itsflanges with a vertical slot l8 through which extends a guide screw I9threaded into the upper portion of the rib 1. Means such as a pair ofsprings 20 engaging at their upper ends so on suitable pins 2| securedto the work support l1 and to pins 22 secured to the rib I beneath theshoulders 8, serve to hold the work support down as far as is permittedby the engagement of its flanges with the wedge member 9. This. mountmgprovides means for adjusting the upper face 25 of the work support withreference to the skiving knife 26, as will later appear. This skivingknife is shown as held by a knife block 21 carried by a rocker member28. This member 0 28 has upstanding ears 2-9 at opposite ends which arecarried on alined pivot elements 30 journaled in the brackets 5 and 6.The pivotal axis is shown in Figure 6 as offset laterally of the rib Iso as to fix the tilting axis of the knife substantially at one edge andclose the top face of the work support, holding a rod 38 supported by anarm 39 extending from a sleeve 40 fixed to the journaled element 4!carried by the rocker member 28 on the opposite side of the bearingbracket 6 against a grooved roller 36. The position of this roller 36 isdetermined by means later to be described.

The top face 25 of the work support I1 is smooth so that the work can beslid thereover u against the edge of the knife 26, and cooperating withthis work support and the knife to hold the work in position, is anupper presser member 45. As shown this presser member is provided with afoot 46 roughened to provide ratchet-like serrations which may engagewith the flesh side of a leather strip to be skived to hold it fromsliding motion relative to the presser member, and while the slide ismoved therebeneath to bring the knife edge against the Work. Thispresser member 45 is slidably mounted in a suitable guideway 41 carriedby a yoke frame 48 which straddles the slide 2 and which may, ifdesired, form a portion of the base member I. The presser member 45 isshown as provided with a stem 49 provided with rack teeth 50 on its rearface with which meshes a toothed segment 5| on one end of .an arm 52.This arm 52 is secured to a pivot shaft 53. Also secured to the shaft 53is a rearwardly extending arm 530 having a socket portion 54 in which isslidably mounted a plunger 55 (see Figure 5), carrying journaled thereonat its lower end a cam roller 56. A spring 51 exerts pressure'againstthe upper face of the plunger 55 to hold the roller 56 down against acam member 58, and the amount of pressure exerted by this spring isadjustable by means of a screw 60 threaded through a cover member 6| ofthe socket portion 54 and engaging on an abutment plate 62 which restson the upper face of the spring 51. nut 63 may be used to fix the screw50 in adjusted position, and an internal shoulder 65 of the socketportion determines the downward limit of motion of the plunger 55, whichis provided with a mating shoulder portion 66. The plunger may beprovided with a slot 61 within which may be engaged a key portion 68 onthe shoulder 65 to hold the plunger against rotation.

The cam roll 56 is normally held into contact with the wedge cam 58, asby a spring I0 engaging the arm 530 at its upper end and a portion ofthe base I at its lower end.

The roller 36 hereinbefore mentioned is journaled at the lower end of anarm I5 which is provided with a sleeve portion 16 at its forward endsecured to the rock shaft 53 as by means of a set screw TI. Thus as thepresser member 45 is raised and lowered relative to the work table, therocker member 28 is rocked on its pivot to vary the inclination of thecutting edge of the knife so that when the presser member is broughtdown into engagement with the upper face of the work to be skived, theangularity of the knife edge is adjusted for the particular thickness ofthe work, the thinner the work the less the inclination of the knife.Varying the proportions of the parts determines the amount of tilt ofthe knife with respect to the position of the presser member 45 so thatany desired relationship between the two may be produced, the tilting ofthe knife being directly proportional to the thickness of the work whichlimits the downward motion of the presser member, or greater or lessthan proportional as may be desired. Where it is greater thanproportional, the thicker the work thevmore pronounced is the shoulderat the rear end of the scarf, which is often desirable.

The cam 58 which moves the presser member 45 up and down to release orengage the upper face of the work is shown as carried by a rotary shaft89 journaled in bracket portions 8| of the machine base. It may beprovided with a large gear 82 which meshes with a driving pinion 84 on adrive shaft 85. This drive shaft may be suitably supported in bracketportions 86 on the A check machine frame and at one end is shown ascarry ing a belt pulley 81 by which it may be driven. This shaft 86 atits rear end is provided with a crank disk 88 having a crank pin 89, anda link 90 engaging over this crank pin is pivotally connected as at 9|at its forward end between ears 92 on the slide 2. The presser beinglifted, the piece, such as a leather strip to be skived, is placed onthe top of the work support 25 in the position shown in Figure 11, withits flesh side up, and preferably in guided relation to a gage 95 whichmay be secured to the member I! at the desired angle to determine theangle of the scarf produced by the machine with relation to the lengthof the work. As shown this gage is arranged to cut the scarf directlyacross and at right angles to the length of the Work.

The work being in this position, rotation of the shaft 80 then actsthrough the cam 58 to bring the presser 45 down against the upper faceof the work with a pressure determined by the initial vertical settingof the worksupport and. the tension of the spring 51. This pressingmember en-. gaging the flesh side of the work firmly holds it againstmovement relative to the presser member 45 and the final downward limitof motion of the presser member, as determined by the thickness of thework, determines the angularity of the knife 26, the edge of which, itwill be noted, is positioned adjacent to and facing one edge of the worksupport 25. The presser member is held down during the completion of thestroke in one direction of the slide 2 as effected by rotation of thecrank pin 89, and the work being held by the presser member 45 againstmotion with the work support and the knife, is caused to be cut by theknife as shown in successive positions in Figures 7, 8, and 9. The knifeis forced into andacross the stationary work, the work support recedingfrom beneath the work as it moves with the knife, the work being heldstationary by its engagement with the roughened foot 46 of the pressermember 45. The presser member 45 holds the work during the entirepressing action either against the upper face of the work support whichslips beneath it or the upper face of the knife.

These figures also show certain refinements of considerable importance.It is desirable that a shoulder be formed at the inner edge of the scarffor the reception of the edge of the mating scarf of the piece which isto be secured thereto. For this purpose, assuming the work beingintroduced from the left as shown, a work-engaging element I00 issecured to the edge of the work support, this element having its topedge projecting above the upper face 25 of the work support andoffsetting the work just in advance of the knife edge as shown in Figure10, so that the knife cuts a shoulder IIJI in the grain side of thework, as shown in Figure 2, to receive the thin edge I02 of the matingpiece which is to be cemented thereto. Likewise, in order to provide aclean cut end edge of the scarf portion and to prevent the waste pieceof material from catching in the knife edge, it is desirable to deflectthe end of the work projecting through between the presser member 45 andthe work support I1. For this purpose a deflector element I03 is shownas secured to the rocker member 28 in position to deflect the end of thework away from the knife edge just in advance of the cutting action.

In order that the mating ends of the two pieces of work may be exactlycomplementally cut, the two pieces of work may be presented fromopposite sides of the work table. Thus for a piece 1 to mate the pieceshown in Figure 11 where the work is extended in from the left handside, the second piece would be extended into the position from theright hand side. In order also to provide for a smooth out, the knifeedge I may be inclined laterally so as to provide for a shearing cutacross the work, this inclination being from the perpendicular to thedirection of relative movement between the knife and the work.

From the foregoing description of an embodiment of this invention, itshould be evident to those skilled in the art that various changes andmodifications may be made without departing from the spirit or scope ofthe invention as defined by the appended claims.

I claim:

1. A skiving machine comprising a flat work support, a skiving knifehaving a cutting edge positioned at one side of said support andarranged at an angle to the plane of its work-supporting face, and meansactuable to move the work relative to the support and knife against saidcutting edge to skive the work.

2. A skiving machine comprising a support for Work to be skived, a knifetilted with reference to said support tobring its cutting edge to thedesired skiving angle and arranged to completely sever the work, saidcutting edge being located adjacent to and facing one edge of saidsupport, a member for holding the work against said support and formedto grip said work, and means for relatively moving said support andknife and said member to effect skiving of the work.

3. A skiving machine comprising a support for work to be skived, a knifetilted to bring its cutting edge to the desired skiving angle, saidcutting edge being located adjacent to and facing one edge of saidsupport, and means for moving said support and knife with reference tothe work on said support to skive the work.

4. A machine of the class described, comprising a work support having asmooth top face for slidably supporting Work, a clamp non-slidablyengaging the top face of the work, a knife, and means for moving saidknife and support relative to the Work and clamp to cause said knife tocut the work.

5. A machine of the class described comprising a work support, a knifehaving a cutting edge positioned at one side of said support and facingwork supported thereon, means for holding the work, and means actuableto move said support and knife while the work is held by said holdingmeans to bring the edge of the knife against and cut the work.

6. A skiving machine comprising a support for work to be skived, askiving knife having a cutting edge positioned above the supporting faceof said support and facing one edge thereof, and means for adjusting theangular relation of said knife to said face about an axis substantiallyin alinement with said face.

7. A skiving machine comprising a support for work to be skived, askiving knife having a cutting edge positioned above the supporting faceof said support and facing one edge thereof, and means for adjusting theangular relation of said knife to said face about an axis substantiallyin alinement with said face and adjacent to one end of said edge.

8. A skiving machine comprising a support for work to be skived, a knifetilted with reference to said support to bring its cutting edge to thedesired skiving angle at one side and above the supporting face of saidsupport, means for moving said work relative to theknife to skive work,and means for clamping said work against said support and said knifeduring the skiving oper-.- ation.

9. A skiving machine comprising. a supportfor work to be skived, a knifetilted with reference to said support to bring its cutting edge to thedesired skiving angle at one side and above the supporting face of saidsupport, means for moving said work relative to the knife to skivevwork,

means for clamping said work against saidsupport and said knife duringthe skiving operation, and means for deflecting the work in advance ofthe knife edge in position to produce a shoulder on the work at theinner margin of the scarf.

10. A skiving machine comprising a support for work to be skived, aknife tilted with reference to said support to bring its cutting edge.to the desired skiving angle at one side and above the supporting faceof said support, means for moving said work relative to the knife toskive the work, means for clamping said work against said support andsaid knife during the skiving operation, and means for deflecting theend portion of the work being skived away from the cutting edge of saidknife.

11. A skiving machine comprising a support for work to be skived, amember movable toward and from said support to clamp the workthereagainst and to release the work, a skiving knife having its cuttingedge presented at one side of said support, means supporting said knifefor rocking to determine the skiving angle, and connections between saidclamp member and supporting means causing the angle of said knife to bedetermined by the spacing of said member from said work support.

12. A skiving machine comprising members for engaging opposite faces ofwork to be skived, one of said membershaving a smooth face over whichthe work may slide and the other member having a face conditioned forfrictional gripping engagement with the work, a. skiving knife having acutting edge arranged adjacent to one edge of said smooth-faced member,and means for relatively moving said knife and smooth-faced member withrespect to said other member to skive the work.

13. A skiving machine comprising a support across which a strip ofmaterial to be skived may be placed, a knife arranged along one side ofsaid support and having a cutting edge tilted to a skiving angle andarranged at one side of said strip, and means for moving said knife andsupport relative tosaid strip laterally of the length of said strip andthrough the full width of said strip to cause said knife to skive thestrip from side to side, said knife edge being inclined to theperpendicular to the direction of skiving motion to produce a shearingcut.

14. A skiving machine comprising a bed, a slide movable on said bed, awork support on said slide, a knife support pivoted to said slide on anaxis substantially parallel to its sliding direction, a skiving knifecarried by said knife support and presenting a cutting edge adjacent toone side of said work support, a presser member movable toward and fromsaid work support to clamp and release work thereon, operativeconnections between said presser member and knife support to vary thetilting angle of said knife edge with movement of said presser member,and means actuable to move said presser member to clamp the work andthen to move said slide to cause the work to be skived, said pressermember having a rough face to hold the work and said work support havinga smooth face to slip beneath the work.

15. A skiving machine comprising a bed, a slide movable on said bed, awork support on said slide, a knife support pivoted to said slide on anaxis substantially parallel to its sliding direction, a skiving knifecarried by said knife support and presenting a cutting edge adjacent toone side of said work support, a presser member movable toward and fromsaid work support to clamp and 'release Work thereon, operativeconnections between said presser member and knife support to vary thetilting angle of said knife edge with movement of said presser member,means actuable to move said presser member to clamp the work and then tomove said slide to cause the work to be skived, said pressure memberhaving a rough face to hold the work and said work support having asmooth face to'slip beneath the work, and a gage member carried by saidwork support determining the angular relation of the work to thedirection of sliding motion of said slide to thereby determine theangularity of the scarf out with relation to the length of the work.

16. The method of skiving a strip of leather, which comprises supportingsaid strip on its grain side for sliding motion relative to its support,exerting non-sliding gripping pressure against the flesh side of saidstrip, and sliding said strip and said support relatively and said striprelative to and against the edge of a skiving knife to skive said stripWhile said gripping pressure is exerted.

HARRY LYON.

